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At least 145 records · Page 8Linked to original sources
PubMed2006

Determination of kavalactones in dried kava (Piper methysticum) powder using near-infrared reflectance spectroscopy and partial least-squares regression.

Kava (Piper methysticum Forst F.), or àwa in the Hawaiian language, has been used for thousands of years by the people of the South Pacific Islands, in particular Fiji, Vanuatu, Tonga, and Samoa, for social and ceremonial occasions. Kava has the unique ability to promote a state of relaxation without the loss of mental alertness. Kava recently became part of the herbal pharmacopoeia throughout the United States and Europe because of its anxiolytic properties. The active compounds are collectively called kavalactones (or kava pyrones). The need for a less time-consuming and costly method to determine the concentration of kavalactones in dried kava is urgent. The combination of near-infrared reflectance spectroscopy (NIRS) and partial least-squares (PLS) methods has been found to be a convenient, versatile, and rapid analytical tool for determination of kavalactones in dried kava powder. Calibration equations were developed based on the analyses of 110 samples with variable physical and chemical properties collected over time from Hawaii kava growers and validated by analyses of a set of 12 samples with unknown kavalactones concentration. All six major kavalactones and the total kavalactones were measured using NIRS with accuracy acceptable for commercial use. The NIRS measurements are reproducible and have a repeatability on a par with HPLC methods.

Anti-Anxiety Agents↗
PubMed2001

Survival strategies of the elderly in Gwembe Valley, Zambia: gender, residence and kin networks.

Fundamental social and material reproductive activities take place in the domestic setting, especially in subsistence societies. For the elderly in these societies, residential arrangements significantly influence their well being because of the redistribution of resources that occurs within the domestic unit. This article examines the critical issue of how the elderly of Zambia's Gwembe Valley organize their residential arrangements. The article also raises the issue of how gender influences elderly men's and women's relationships and support networks with their children and other kin. In the Gwembe Valley men and women employ different strategies in harnessing basic necessities, including their residence, which constitutes the primary setting where people negotiate their needs. Recognition of the variety and subtlety of relationships in the aging process, and the variety of individuals engaged in those relationships, allows for better understanding of the range of support systems and subsistence strategies in non-industrial settings. The analysis presented in this article emerges from the longitudinal Gwembe Tonga Research Project (GTRP) and ethnographic fieldwork carried out in three rural communities during the mid 1990s.

Journal Article↗
PubMed2003

A view from the other side: the place of spirits in the Tongan social field.

Spirits are part of everyday life in the Kingdom of Tonga. This study explores beliefs about the supernatural by analyzing discourse on spirits and death and by examining two examples of contemporary cultural practice related to spirits and death. The anthropological concepts of the body and its cultural construction and of thirdspace as a landscape of the Tongan islands that emerges out of the physical and the perceived provide the framework for this investigation. Research findings suggest that spirits participate in the natural order of Tongan society and thus serve to help maintain cultural identity in the face of uncertain social change and a popular but contested prodemocracy movement. Spirits also function as a system of representation, mirroring an image of an ideal self, something that is continually under negotiation. Encounters between spirits of ancestors and their living descendants suggest an uneasy acceptance of death and a sense of irony about its inevitability.

Culture↗
PubMed2002

Mid-mantle deformation inferred from seismic anisotropy.

With time, convective processes in the Earth's mantle will tend to align crystals, grains and inclusions. This mantle fabric is detectable seismologically, as it produces an anisotropy in material properties--in particular, a directional dependence in seismic-wave velocity. This alignment is enhanced at the boundaries of the mantle where there are rapid changes in the direction and magnitude of mantle flow, and therefore most observations of anisotropy are confined to the uppermost mantle or lithosphere and the lowermost-mantle analogue of the lithosphere, the D" region. Here we present evidence from shear-wave splitting measurements for mid-mantle anisotropy in the vicinity of the 660-km discontinuity, the boundary between the upper and lower mantle. Deep-focus earthquakes in the Tonga-Kermadec and New Hebrides subduction zones recorded at Australian seismograph stations record some of the largest values of shear-wave splitting hitherto reported. The results suggest that, at least locally, there may exist a mid-mantle boundary layer, which could indicate the impediment of flow between the upper and lower mantle in this region.

Journal Article↗
PubMed2004

Origins and dispersals of Pacific peoples: evidence from mtDNA phylogenies of the Pacific rat.

The human settlement of the Pacific in general, and the origin of the Polynesians in particular, have been topics of debate for over two centuries. Polynesian origins are most immediately traced to people who arrived in the Fiji, Tonga, and Samoa region approximately 3,000 B.P. and are clearly associated with the Lapita Cultural Complex. Although this scenario of the immediate origins of the Polynesians is generally accepted, the debate on the ultimate origin of the Polynesians and the Lapita cultural complex continues. Our previous research has shown that analyses of mtDNA variation in the Pacific rat (Rattus exulans), often transported as a food item in the colonizing canoes, are valuable for tracing prehistoric human migration within Polynesia. Here we present mtDNA phylogenies based on approximately 240 base pairs of the d-loop from both archaeological and modern samples collected from Island Southeast Asia and the Pacific. We identify three major haplogroups, two of which occur in the Pacific. Comparing our results with Lapita models of Oceanic settlement, we are able to reject two often cited but simplistic models, finding support instead for multifaceted models incorporating a more complex view of the Lapita intrusion. This study is unique and valuable in that R. exulans is the only organism associated with the Lapita dispersal for which there are sufficient ancient and extant populations available for genetic analysis. By tracking population changes through time, we can understand more fully the settlement process and population interactions in both Near and Remote Oceania.

Animals↗
PubMed2002

Rapid prehistoric extinction of iguanas and birds in Polynesia.

The Tongoleleka archaeological site on Lifuka Island, Kingdom of Tonga, is a rich accumulation of pottery, marine mollusks, and nonhuman bones that represents first human contact on a small island in Remote Oceania approximately 2,850 years ago. The lower strata contain decorated Lapita-style pottery and bones of an extinct iguana (Brachylophus undescribed sp.) and numerous species of extinct birds. The upper strata instead feature Polynesian Plainware pottery and bones of extant species of vertebrates. A stratigraphic series of 20 accelerator-mass spectrometer radiocarbon dates on individual bones of the iguana, an extinct megapode (Megapodius alimentum), and the non-native chicken (Gallus gallus) suggests that anthropogenic loss of the first two species and introduction of the latter occurred on Lifuka within a time interval too short (a century or less) to be resolved by radiometric dating. The geologically instantaneous prehistoric collapse of Lifuka's vertebrate community contrasts with the much longer periods of faunal depletion on some other islands, thus showing that the elapse time between human arrival and major extinction events was highly variable on oceanic islands as well as on continents.

Animals↗
PubMed2006

Illicit drug use and responses in six Pacific Island countries.

We report here on the illicit drug situation in six Pacific nations: Fiji, Papua New Guinea, Samoa, Solomon Islands, Tonga and Vanuatu. The report is based on the 'Situational analysis of illicit drug issues and responses in Asia and the Pacific', commissioned by the Australian National Council on Drugs Asia Pacific Drug Issues Committee. The situational analysis was a comprehensive desk-based review; data sources included published and unpublished literature and information from key informants. A range of psychoactive substances have been used traditionally across the Pacific region. Cannabis is the by far the most common and widespread illicit drug used in the six Pacific Islands reviewed. Drugs such as heroin, methamphetamines and cocaine are not used commonly due to their high cost compared to the average income. Currently, there is no overall regional or country-based illicit drug policy for the Pacific and few treatment programs; limited data exist to aid in understanding illicit drug use and the harms associated with its use in the Pacific. This review highlights the urgent need for strategic alcohol and drug research in the Pacific as a foundation for the development of policy.

Criminal Law↗
PubMed1997

Alcohol in the South Pacific: the mid-1990s.

In the mid-1990s data were obtained on alcohol consumption in the Cook Islands, Fiji, Kiribati, Samoa, the Solomon Islands and Tonga. These data are reported together with a discussion of the nature of alcohol related problems in the island nations. Per capita consumption is highest in the Cook Islands, which compared with other countries has the highest ratio of liquor outlets and lowest alcohol taxation regime. As an alcohol problem prevention measure, it is concluded that the promotion of responsible consumption, together with the option of abstinence for those who wish it, is an acceptable strategy for the Pacific.

Journal Article↗
PubMed2005

Health behaviour and lifestyle of Pacific youth surveys: a resource for capacity building.

The changing global socio-economic environment over the last two decades has had significant ramifications for the health and development of youth in lower- and middle-income countries. In the Pacific region, young people are exposed to similar causes of ill-health as their peers in developed countries. This paper describes the development, implementation and major findings of the Health Behaviour and Lifestyle of Pacific Youth (HBLPY) surveys, a regional initiative to obtain representative data about health-related behaviour and needs of adolescents in Vanuatu, Tonga and the Federated States of Micronesia. The Pacific HBLPY is modelled on the WHO Europe Health Behaviour in School-aged Children (HBSC) surveys. The surveys, undertaken in 2000-2001, were built upon strong local partnerships and were undertaken with youth participation to ensure survey ownership. A regional technical group was formed to provide training and support to strengthen health survey capacity of youth and their agencies. The findings showed that tobacco was most commonly used substance, with 29.7% of 15-year-old boys and 15.7% of girls smoking weekly. Over half of the students did not engage in physical activity for at least 2 h per week; these rates are substantially lower than those usually found in Europe. Dietary habits among this group are also of concern, reflecting international trends away from highly nutritious traditional diets. The HBLPY surveys have shown that it is possible to collect population-based data in lower- and middle-income countries so that appropriate youth health programmes and policies can be developed. Implementation of an ongoing surveillance system similar to the HBLPY model in these countries warrants further investigation. Such initiatives should be supported at the regional and global level.

Adolescent↗
PubMedDate not supplied

Evidence for long isolation among populations of a pacific cycad: genetic diversity and differentiation in Cycas seemannii A.Br. (Cycadaceae).

The genetic structure of Cycas seemannii A.Br. (Cycadaceae), sampled throughout its range in Vanuatu, New Caledonia, Fiji, and Tonga, was studied using starch-gel electrophoresis. Twenty enzyme loci in 13 enzyme systems were examined. Low genetic diversity within populations (A = 1.2, P = 21.3, Ho = 0.047, and He = 0.057) and a high degree of differentiation among populations (F(ST) = 0.594) were found. This, together with low gene flow estimates, suggests genetic drift by isolation to have been most critical to the current genetic structure of the species. Inbreeding may occur to some extent (F(IS) = 0.165). The decline in abundance of C. seemannii, coupled with the low level of genetic diversity, suggest that conservation strategies are urgently needed.

Analysis of Variance↗
PubMed1991

Purification, characterization and serological detection of virus-like particles associated with banana bunchy top disease in Australia.

Isometric virus-like particles, 18 nm in diameter, have been isolated from banana (Musa spp.) affected by bunchy top disease in Australia. Banana bunchy top disease-associated virus-like particles (BBTV) banded as a single component with buoyant density of 1.28 to 1.29 g/ml in Cs2SO4 and sedimented at about 46S in isokinetic sucrose density gradients. The A260/A280 of purified preparations was about 1.33. A single coat protein of Mr 20,500 was identified with antibodies to BBTV particles from Australia. Single-stranded DNA of about 1 kb as well as ssRNA smaller than 0.45 kb was also associated with the particles. A polyclonal antiserum to BBTV, suitable for use in ELISA, was prepared. Stability and antigenicity of purified BBTV was impaired by storage at pH greater than or equal to 8.5 and freezing at -20 degrees C without protectants. BBTV was detected by double antibody sandwich-ELISA with monoclonal and polyclonal antibodies, in field-infected banana plants, single aphids from an infective colony, and in experimentally aphid-inoculated banana plants. After transmission of BBTV particles by aphids from a banana bunchy top disease-affected to an uninfected banana plant, the disease was induced and BBTV was detected by ELISA in symptomatic leaves only. BBTV isolates from Australia, Taiwan, People's Republic of China, Tonga, Western Samoa and Hawaii were found to be serologically related, which suggests a common aetiology for the disease.

Animals↗
PubMed1994

Evidence for two groups of banana bunchy top virus isolates.

Banana bunchy top virus (BBTV) DNA component 1 from isolates from 10 different countries was cloned and sequenced and the sequences were aligned and compared. This analysis indicated two groups: the South Pacific group (isolates from Australia, Burundi, Egypt, Fiji, India, Tonga and Western Samoa) and the Asian group (isolates from the Philippines, Taiwan and Vietnam). The mean sequence difference within each group was 1.9 to 3.0% and between isolates from the two groups was approximately 10%, but some parts of the sequences differed more than others. However, the protein encoded by the major open reading frame, which is probably a replicase, differed by approximately 5%. The region from the beginning of the stem-loop sequence to the potential TATA box was identical in all isolates except for a two nucleotide change in the Western Samoan isolate and a single change in that of the NSW isolate. These results, together with other evidence, suggest that BBTV has spread to bananas after the initial movement of bananas from the Asian Pacific regions to Africa and the Americas.

Africa↗
PubMed1994

Hierarchical structure of mitochondrial DNA gene flow among humpback whales Megaptera novaeangliae, world-wide.

The genetic structure of humpback whale populations and subpopulation divisions is described by restriction fragment length analysis of the mitochondrial (mt) DNA from samples of 230 whales collected by biopsy darting in 11 seasonal habitats representing six subpopulations, or 'stocks', world-wide. The hierarchical structure of mtDNA haplotype diversity among population subdivisions is described using the analysis of molecular variance (AMOVA) procedure, the analysis of gene identity, and the genealogical relationship of haplotypes as constructed by parsimony analysis and distance clustering. These analyses revealed: (i) significant partitioning of world-wide genetic variation among oceanic populations, among subpopulations or 'stocks' within oceanic populations and among seasonal habitats within stocks; (ii) fixed categorical segregation of haplotypes on the south-eastern Alaska and central California feeding grounds of the North Pacific; (iii) support for the division of the North Pacific population into a central stock which feeds in Alaska and winters in Hawaii, and an eastern or 'American' stock which feeds along the coast of California and winters near Mexico; (iv) evidence of genetic heterogeneity within the Gulf of Maine feeding grounds and among the sampled feeding and breeding grounds of the western North Atlantic; and (v) support for the historical division between the Group IV (Western Australia) and Group V (eastern Australia, New Zealand and Tonga) stocks in the Southern Oceans. Overall, our results demonstrate a striking degree of genetic structure both within and between oceanic populations of humpback whales, despite the nearly unlimited migratory potential of this species. We suggest that the humpback whale is a suitable demographic and genetic model for the management of less tractable species of baleen whales and for the general study of gene flow among long-lived, mobile vertebrates in the marine ecosystem.

Animals↗
PubMed2005

Patterns of genetic variation do not correlate with geographical distance in the reef-building coral Pocillopora meandrina in the South Pacific.

Dispersal may be a critical factor in the ability of reef-building corals to recover after major disturbances. We studied patterns of geographical structure using four microsatellite markers in seven South Pacific populations of Pocillopora meandrina, a major coral species from Polynesia. Variation within populations showed evidence of heterozygote deficiency. Genetic differentiation between populations was detected at a large scale (2000 km) between the Tonga and the Society Islands. Within the Society Islands, four of the five studied populations from Bora Bora, Moorea and Tahiti were not significantly different from each other. Unexpectedly, one of the three populations surveyed in Moorea was genetically different from the other two populations of this island (that were 5 and 10 km apart), and from the populations of the other two surveyed islands in this archipelago. We cannot rule out the possibility that this pattern is an equilibrium state, whereby short-range dispersal is locally more differentiating than long-range dispersal, as has been suggested by similar patterns reported in other studies. An alternative explanation that is globally consistent with all observations is that this is the signature of a large-scale destruction event, as for instance a bleaching event, followed by the recent restoration of populations by new colonists.

Animals↗
PubMed1998

Human rights of psychiatrically disturbed persons in the tropical Pacific.

The management of acutely disturbed patients in smaller Pacific island communities presents many clinical challenges as well as ethical and human rights questions. The aggressive, excited, sexually inappropriate, and possibly violent disturbed person frequently will need physical restraint and possible seclusion in a secure environment. In practical terms, on many Pacific islands the only physically secure room is a jail cell. This environment will protect others and possibly protect the out-of-control person from themselves. After protection, the next requirements are adequate information about the person and clinically informed individuals who can make a diagnosis and commence treatment in the jail environment. Adequately trained people who can diagnose and suggest initial treatment are few and widely dispersed in Pacific island communities. Two representative case vignettes from the author's experience as a World Health Organization short-term consultant in Tonga and the Commonwealth of the Northern Mariana islands illustrate the tension between a disturbed person's right to adequate treatment and the right of a citizen/patient to be free of coercion.

Adult↗
PubMed2001

Repeating deep earthquakes: evidence for fault reactivation at great depth.

We have identified three groups of deep earthquakes showing nearly identical waveforms in the Tonga slab. Relocation with a cross-correlation method shows that each cluster is composed of 10 to 30 earthquakes along a plane 10 to 30 kilometers in length. Some of the earthquakes are colocated, demonstrating repeated rupture of the same fault, and one pair of events shows identical rupture complexity, suggesting that the temporal and spatial rupture pattern was repeated. Recurrence intervals show an inverse time distribution, indicating a strong temporal control over fault reactivation. Runaway thermal shear instabilities may explain temporally clustered earthquakes with similar waveforms located along slip zones weakened by shear heating. Earthquake doublets that occur within a few hours are consistent with events recurring before the thermal energy of the initial rupture can diffuse away.

Journal Article↗
PubMed2001

Seismic detection of rigid zones at the top of the core.

Data from earthquakes in the Tonga-Fiji region recorded at a seismic array in northern Australia show evidence for rigid zones at the top of the outer core. The ScP waveforms can be modeled by thin (0.12 to 0.18 kilometer) zones of molten iron mixed with solid material with a small, but positive, S-wave velocity (0.6 to 0.8 kilometer per second) that enables the propagation of S-waves in the outermost core. The zones may be topographic highs of the core-mantle boundary filled by light core sediments and might be important for variation of Earth's nutation and for convection of the outer core.

Journal Article↗
PubMed2001

Evidence for a large-scale remnant of subducted lithosphere beneath Fiji.

We combine spatial variations of P- and S-wave speeds, 1000 fault plane solutions, and 6600 well-determined hypocenters to investigate the nature of subducted lithosphere and deep earthquakes beneath the Tonga back-arc. We show that perplexing patterns in seismicity and fault plane solutions can be accounted for by the juxtaposition of a steep-dipping Wadati-Benioff zone and a subhorizontal remnant of slab that is no longer attached to the actively subducting lithosphere. The detached slab may be from a previous episode of subduction along the fossil Vitiaz trench about 5 to 8 million years ago. The juxtaposition of slabs retains a large amount of subducted material in the transition zone of the mantle. Such a configuration, if common in the past, would allow the preservation of a primordial component in the lower mantle.

Journal Article↗